In order to explore the potential of non-invasive techniques - such as self-referencing electrodes - to assess the viability of pre-implantation embryos it is clearly necessary to keep these early embryos in a healthy state during examination. Surprisingly, given the importance of reproductive physiology to women's health, there is little limited success in this area. However, using a slight modification to a media already designed for embryo studies we were able to design a set-up that allowed maximal access to the embryos by the electrodes through the air water interface of a 35mm dish. No oil was required thus minimizing the contamination of the electrodes. The Faraday box was changed into a temperature controlled environment using the microscope and air-table as a heat sink. Initial attempts with commercially available heating units were disastrous with thermal gradients affecting the different expansion coefficients of the electrode set-up, causing pronounced drift during experime nts.Using this system we are now able to measure ionic fluxes from mammalian single cell embryos up to the blastocyst stage. We have an experimental window of approximately two hours after which the mouse embryos can be transferred into a pseudo-pregnant recipient and born 19 days latter as healthy mice.